1. Field of the Invention
The present disclosure is directed to an improved optimal tire performance indicator.
2. Description of the Related Art
The tread is the part of a tire that comes in contact with the road surface. The portion in contact with the road at a given instant in time is known as the contact patch or footprint. The tread may be a thick rubber, or rubber/composite compound formulated to provide an appropriate level of traction that does not wear away too quickly. The tread pattern is characterized by the geometrical shape of the grooves, blocks, voids and sipes. Grooves run generally circumferentially around the tire, and are structured to channel away water. Blocks (or lugs) are that portion of the tread design that contacts the road surface. Voids are spaces between blocks (or lugs) that allow the blocks to flex and also provides spaced for water to evacuate. Tread patterns may feature non-symmetrical (or non-uniform) lug sizes circumferentially in order to minimize noise levels at discrete frequencies.
Hydroplaning, also known as aquaplaning, is the condition where a layer of water builds up between the tire and road surface. Hydroplaning occurs when the grooves in the tread pattern cannot channel away enough water at an adequate rate to ensure a semi-dry footprint area. When hydroplaning occurs, the tire effectively “floats” above the road surface on a cushion of water, thereby losing traction, braking and steering, creating a very unsafe driving condition. When hydroplaning occurs, there is considerably less responsiveness of the steering wheel.
Tread wear, also known as tire wear, is caused by friction between the tire and the road surface. As a tire wears, traction (e.g., dry traction, wet traction and snow traction) is reduced as compared to a new tire. Thus, proper vehicle safety requires specific attention to tread depth and general condition of the tires (amongst other conditions). Moreover, a tire retains optimal performance for certain weather (and road) conditions (e.g., snowy conditions, rainy conditions, and/or sunny conditions) for only part of the tire's service life. For example, a tire that is initially suitable for snowy road conditions (and rainy and sunny conditions), may experience tread wear to such an extent that the tire no longer provides adequate traction in snowy conditions, while still remaining safe for rainy and/or sunny (or dry) road conditions.
To alert the driver when a tire has reached, or is approaching, its wear limit, wear bars (or wear indicators) or other raised features can be located near the bottom of the tread grooves to provide a visible indicator. When the tread lugs are worn to the point that the wear bars connect across the lugs, the tires can be understood to be fully worn and ready to be taken out of service. Some wear indicators additionally function as performance indicators, indicating a degree or extent of wear, e.g., using a numerical scale or weather symbols integrated within the tread pattern.
However, with conventional wear indicators, the tire owner cannot tell easily at which point the optimal service is no longer available. That is, as existing tire performance indicators integrate the numerical scale or weather symbols within the tread pattern of the tire, a tire owner's view of the indicator may be obstructed by the positioning of the vehicle housing relative to the tire, so that the owner cannot easily observe such tire performance indicators located within the tread pattern. As such, it is difficult for a tire owner, for example, to observe the current wear state of the tire, and thus, difficult to determine when the optimal service for certain conditions (e.g., for snowy conditions, rainy conditions, and/or sunny conditions) has been exceeded.
Therefore, there is a need for an improved optimal tire performance indicator.